I have standalone Laptop 11th Gen Intel (first framework generation) that works as a PC. It’s always connected to a monitor and the mainboard led indicator is always turned on. Can I disconnect it from the power/electricity or will it damage the mainboard with constant turn-on/off from power.
If you have shutdown the computer from your operating system and the device is off, there is no issue disconnecting the power adapter (by either unplugging or say using a switch from a power strip).
Pulling power from a standalone Framework board while it is running is not a great idea and likely would corrupt the operating system.
On the 11th gen boards just make sure the power is plugged into the standalone board about once every two weeks to keep the RTC battery charged. (The coin cell battery found on most motherboards is normally an alkaline cell) The battery on the 11th gen boards is rechargeable. Letting it discharge to low levels over a long period of time (months) degrades the charge capacity of the cell.
Most modern USBC power adapters (like the one Framework sells for this machine) is pretty power efficient even in standby.
Side note: There is a setting in the BIOS to wake on power applied to the board; if that is enabled then when power is plugged back in or say the power strip is turned on the board should power up on its own. It would be interesting to get a smart switch and connect it to a voice assistant. You could in theroy, wake up and power off the machine/monitor with a voice command like, “Alexa, turn on Framework”